Factorial

Save all functions into the same file named comb.py.

1. Write the function factorial() that computes the factorial of a given integer. Examples:

   >>> factorial (1)
   1
   >>> factorial (5)
   120
   >>> factorial (8)
   40320
   >>> factorial (10)
   3628800
   

   Note

   More tests are provided in file test-factorial.txt

2. Use the preceding function and write the function combinatorial() that takes two positive integes n and m, and returns the combinatorial number \({n \choose m} = {n! \over {m! (n-m)!}}\). Examples:

   >>> combinatorial(1,1)
   1
   >>> combinatorial(8, 5)
   56
   

   Note

   More tests are provided in file test-combinatorial.txt

Solution

A solution of these functions is provided in the comb.py file.